BAGHDAD — The Islamic militants who overran cities and towns in Iraq last week posted graphic photos that appeared to show their gunmen massacring scores of captured Iraqi soldiers, while the prime minister vowed Sunday to “liberate every inch” of captured territory.

The pictures on a militant website appear to show masked fighters of the Islamic State of Iraq and the Levant, known by the acronyms ISIL or ISIS, loading the captives onto flatbed trucks before forcing them to lie facedown in a shallow ditch with their arms tied behind their backs. The final images show the bodies of the captives soaked in blood after being shot.

Lt. Gen. Qassim al-Moussawi, chief military spokesman, confirmed the photos’ authenticity and said he was aware of cases of mass murder of captured Iraqi soldiers in areas held by ISIL. He told The Associated Press that an examination of the images by military experts showed that about 170 soldiers were shot to death by the militants after their capture.

U.S. State Department spokeswoman Jen Psaki said the militants’ claim of killing the Iraqi troops “is horrifying and a true depiction of the bloodlust that those terrorists represent.”

She added that a claim that 1,700 were killed could not be confirmed by the U.S.

On Friday, U.N. human rights chief Navi Pillay warned against “murder of all kinds” and other war crimes in Iraq, saying the number killed in recent days may run into the hundreds. She said in a statement that her office had received reports that militants rounded up and killed Iraqi soldiers as well as 17 civilians in a single street in Mosul. Her office also heard of “summary executions and extrajudicial killings” after militants overran Iraqi cities and towns, she said.

The grisly images could sap the morale of Iraq’s security forces, but they could also heighten sectarian tensions. Thousands of Shiites are already heeding a call from their most revered spiritual leader to take up arms against the Sunni militants who have swept across the north in the worst instability in Iraq since the U.S. withdrawal in 2011.

The USS George H.W. Bush arrived in the Persian Gulf as President Barack Obama considers possible military options, although he has ruled out putting American troops on the ground in Iraq.

Pentagon spokesman Rear Adm. John Kirby has said the move will give Obama additional flexibility if military action were required to protect American citizens and interests in Iraq.

Iraqi government officials said ISIL fighters were trying to capture the city of Tal Afar in the north and firing rockets seized from military arms depots. The officials said the local garrison suffered heavy casualties and the main hospital was unable to cope with the wounded, without providing exact numbers.

Al-Moussawi confirmed fighting was raging at Tal Afar, but indicated that the militants were suffering heavy casualties.

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Security beefed up at embassy in baghdad

WASHINGTON — The Defense Department has sent a contingent of about 150 Marines to provide security for the massive U.S. Embassy in Baghdad, and the State Department on Sunday ordered some embassy personnel to relocate to safer parts of Iraq or to leave the country.

“As a result of ongoing instability and violence in certain areas of Iraq,” State Department spokeswoman Jen Psaki said, “some” of the more than 5,000 embassy personnel are being sent to consulates in Basra, in the far south, and Irbil, in the northern Kurdish region. Others are being relocated to Jordan.

This is the first time since the U.S.-led invasion in 2003 that the embassy has decreased its staffing levels in response to a threat posed by violence.

“Overall, a substantial majority of the U.S. Embassy presence in Iraq will remain in place, and the Embassy will be fully equipped to carry out its national security mission,” Psaki said in a statement.

The announcements came as Secretary of State John Kerry made calls to his counterparts in Jordan, Saudi Arabia, the United Arab Emirates and Qatar to discuss the crises in Iraq and Syria.

American contractor personnel were evacuated beginning late last week from two Iraqi bases, in Balad and Taji, and from an oil refinery and power plant in Baiji.

The State Department issued a travel warning for Iraq on Sunday night that cautioned U.S. citizens to avoid “all but essential travel to Iraq.”

Oil price soars as conflict widens •NEW YORK — Brent crude was projected by Wall Street analysts to average as much as $116 a barrel by the end of the year. Now, with violence escalating in Iraq, how far the price will rise has become anyone’s guess. The international benchmark surged above $114 on June 13 for the first time in nine months as militants routed the Iraqi army in the north and advanced toward Baghdad, threatening to ignite a civil war. The Islamic State of Iraq and the Levant, known as ISIL, has halted repairs to the pipeline from the Kirkuk oil field to the Mediterranean port of Ceyhan in Turkey. Denver Post wire services

The owners of Boulder’s Sterling University Peaks apartments, who this summer were cited for illegally subdividing 92 bedrooms in the complex, have reached an agreement to settle the case for $410,000, the city announced Thursday.